Plug cap



Sept. 14, 1937.` E. J. TE PAs ET AL PLUG ,CAP

' INVENTORS Edmund J TePas By Vlter.l/"rantz @Q ffl /J ATTOR Filed Aug.8, 1933 Patented Sept. 14, 1937 UNITED STATES PATENT OFFICE PLUG CAP Ysignor to said Frantz Application August 8, 1933, Serial No. 684,194

6 Claims.

This invention relates to electrical connectors as for example theterminal plug caps of attachment plugs for electrical cords and it hasfor its object the provision of adevice of this character which is notliable tov breakage, which is not liable to electrical short circuiting,and which is not apt to become detached from the cord or to have theelectrical connection broken between the plug contacts and the conductorstrands of the cord, the aforesaid objects being accomplished throughthe use of a simple and inexpensive form of plug cap construction whichcan be readily attached to an electric cord by persons unskilled andinexperienced in the construction of electrical devices and appliances.

With these and other objects in View, the invention consists in thenovel construction, arrangement and combination of parts, hereinafterillustrated and described in some of its embodiments in the accompanyingdrawing, and particularly pointed out in the appended claims.

In the drawing Figure 1 is a side elevational view of a plug capillustrating one form of carrying out this invention; Figure 2 is asectional view taken on line 2 2, Figure 1; Figure 3 is a sectional viewtaken on line 3 3, Figure 2; Figure 4 is a sectional view taken on theaxis of a modified form of plug cap; Figure 5 is a sectional View takenon line 5 5, Figure 4; Figure 6 is a detail view of one of the contactprongs of the plug cap shown in Figure 4; Figures 7 and 8 are end viewsof slightly modified forms of plug caps and cords in which the plug capsfollow generally the construction shown in Figure 4; Figure 9 is adetail view of another modified form of cord construction; and Figure 10is a fragmentary sectional view of a. modified form of plug constructionsimilar to the form shown in Figure 4.

'I'hree forms of plug caps are shown in the drawing for purposes ofillustrating some of the different modes of carrying out this invention.The plug cap shown in Figures 1 to 3 comprises a soft rubber-likeelectrically non-conducting plug cap body I having contact prongs 2projecting from the outer end thereof. These prongs may be detachablyassociated with the cap body I as shown in Wermine U. S. Patent No.1,858,196 issued May 10, 1932 or they may be anchored in this body atthe time it is molded, in which case holes 8 would be formed in theprongs to permit the material of the plug cap to flow through the prongsfor insuring their better securement. The body I is slit along oppositesides whereby access may be had tothe hollow interior of the plug cap.

The concealed ends of the contact prongs inside the hollow interior ofthe plug end abut against a depending portion 9 integrally formed withthe plug. The contact prongs are threaded for reception of the screws 3by means of which the conductor strands 4 of a cord 5 are secured to thecontact prongs after which operation has been performed the slittedportion of the plug may be allowed to assume its normal positionwhereupon the complementary parts 6 forming the sleeve of the plug maybe anchored to the cord by means of binding the same with a string orwire l.

The modification shown in Figures 4 to 8 comprises an integrally formedplug cap body I0 formed from a soft rubber-like electricallynonconducting material of molded construction in which are permanentlyembedded a pair of contact prongs II. The central interior portion ofthe plug cap body is formed with a longitudinally grooved passageway I2for receiving a cord I3 which has a longitudinally corrugated exteriorsurface complementary to the surface of the passageway I2. The exteriordiameter of the cord and the diameter of the passageway I2 aresubstantially the same so that the cord freely yet closely fits withinthe plug.

'I'he plug cap is provided at one end with a sleeve Il which may berolled up as shown in Figure 4 to cause this portion of the plug cap tofirmly grip the cord. The complementary contacting surface of the cordand the plug cooperate at g the same time to prevent twisting of thecord within the plug. The conductor strands I5 of the cord are securedto the contact prongs by means of suitable screws IB.

lA washer I'I having apertures for receiving the prongs II is fittedover the screws Il and the exposed ends of the conductor strands I5.Each of the contact prongs I I has a folded over portion I8 and abent-over part 20 which is provided with an aperture 2I. These parts ofthe plug are embedded within the body of the plug and the material ofthe plug will ow between the bent-over parts I8 and through the aperture2'I whereby the contact prongs II are firmly anchored in the plug.

The cords I3l and 22 shown in Figures 7 and 8 are provided withldifferent forms of surface covering and when a cord of this type is usedthe passageways I2a and I2h of the plug caps I I and I4h would beprovided with a surface complementary to the surface of the cord. Thecarrying out of this feature of the invention would also be accomplishedin some degree by having the may have a looser fit than is necessary inac-v complishing the same results with a plug cap having a smoothlyfinished cord passageway.

In the modified form of plug cap constructionV shown in Figure 10 theplug cap body 2d is provided with a sleeve portion 25 terminating in athickened annular end portion 26 within which there is vulcanized one ormore turns of cord 2l so that when the plug cap is attached in positionon the cord 28 the end portion 2l is rolled over the annular thickenedsleeve part 29 and the cord 2l is thus tensioned placing the rubberbeneath it in compression whereby the cord is rmly gripped by the plugcap. The thickened portion Mlm of the sleeve of the plug shown in Figure4 is provided to prevent the unrolling of the rolledup sleeve Ml.

Furthermore it is to be understood that the particular forms ofapparatus shown and described, and the particular procedure set forthare presented for purposes of explanation and 30 that variousmodifications of said apparatus and procedure can be made withoutdeparture from this invention as described in the appended claims.

Having thus described our invention what we claim is:

l. An attachment plug cap for use in connection with a flexible electriccord having conductor strands comprising an integrally formed softrubber-like body, contact prongs carried by said body, means forconnecting the conductor strands to said prongs, said body having apassageway the walls of which are complementary to the surface of thecord, the cord being of irregular outline in cross-section wherebytwisting of the cord in the plug is prevented, and means for anchoringsaid cord to said body.comprising a rolled-up sleeve carried by. andforming a part of said body.

2. An attachment plug cap for use in connection with a flexible electriccord having conductor strands comprising an integrally formed softrubber-like body of molded construction with a sleeve extendingtherefrom, contact prongs xedly carried by said body, and means forconnecting the conductor strands to said prongs, said body and sleevehaving`a passageway the walls of which are complementary to the surfaceof the cord, the cord being non-circular in cross-section wherebytwisting of the cord in the plug is preamasar vented, said sleeve beingrolled-up to anchor the plug cap to the cord.

3. An attachment plug cap for use in connection with a flexible electriccord having conductor strands comprising an integrally formed softrubber-like body, contact prongs embedded in said body with portions ofsaid body extending over bent-over parts of said prongs for anchoringthe'sarne in said body, means for connecting the conductor strands tosaid prongs, said body having a passageway the walls of which arecomplementary to the surface of the cord, the cord being non-circular incross-section whereby twisting of the cord in the plug is prevented, andmeans for anchoring said cord to said body comprising a rolled-up sleevecarried by and forming a part of said body.

4. An attachment plug cap for use in connection with a longitudinallycorrugated exible electric cord having conductor strands comprising anintegrally formed soft rubber-like body, with a sleeve extendingtherefrom, contact prongs embedded in said body, and means forconnecting the conductor strands to said prongs, said body and sleevehaving a passageway the walls of which have corrugations complementaryto those on the cord, the cord being non-circular in cross-sectionwhereby twisting of the cord in theplug is prevented, said sleeve beingrolled-up to anchor the plug cap to the cord.

5. An attachment plug cap for use in connection with a exible electriccord having conductor strands comprising an integrally formed softrubber-like body, contact prongs having bent-over portions embedded insaid body and surrounded by the material thereof, means for connectingthe conductor strands to said prongs, said body having a passageway thewallsof which are complementary to the surface of the cord, the cordbeing non-circular in cross-'section whereby twisting of the cord in theplug is prevented, and means for anchoring said cord to said bodycomprising a rolled-up sleeve carried by and forming a part of saidbody.

6. An attachment plug cap for use in connection with a exible electriccord having conductor strands comprising an integrally formed softrubber-like body, Contact prongs carried by said body, means forconnecting the conductor strands to said prongs, and meansV foranchoring said cord to said body comprising a rolled-up sleeve carriedby and forming a part of said body, said sleeve having embedded thereina substantially non-extensible element encircling said cord and placingthe material therebeneath in compression whereby the plug cap firmlygrips the cord.

EDMUND J. TE PAS. WALTER. A. FRANTZ.

